GB475798A - Improvements in or relating to electric motor controllers - Google Patents

Abstract

475,798. Actuating controllers. GENERAL ELECTRIC CO., Ltd., and CROFT, E. H. May 22, 1936, No. 14535. [Class 38 (iii)] An electric motor speed controller, more particularly for a trolly bus, comprises an operating pedal which, over one part of its range of movement, operates one or more contacts directly, and over another part of its range of movement operates a contact which remains operated until movement of the pedal in the reverse direction exceeds a predetermined amount, the operating circuits of the motor remaining unchanged unless such reverse movement exceeds the predetermined amount. Switches controlling the motor shunt field regulating resistance comprise a pivoted contact arm 22 connected by a spring 24 to a pivoted lever 23 spring biassed so that a roller 28 engages a cam 25. The cams 25 are mounted on a pedal-operated shaft on which a master controller controlling the line switches and the series field and armature resistance switches are mounted. Upon rotation of the shaft the cams 25 are operated and the links 23 rotated to carry their springs 24 across a dead centre and effect quick make or break between the contacts 21, 26. In a modification, Fig. 3, a drum controller 31 for the shunt field is mounted coaxially with a pedal-operated master controller 32, and connected thereto by a dog-clutch 34 which allows a degree of free movement between the drum controller and the pedal shaft.